Right ventricular (RV) failure is known to occur in 10-15% of patients following left ventricular assist device (LVAD) placement. In addition, acute RV failure following orthotopic cardiac transplantation is also known to occur, and may be related to RV stunning at the time of organ harvest and administration of cardioplegia. RV failure in these settings is often reversible, not requiring long term mechanical support. Currently, commercially available devices approved for RV assist involve the surgical placement of either centrifugal or pulsatile devices, all of which require surgical operation for both placement and device removal. A percutaneously placed right ventricular assist device, if available, could spare patients the risk resulting from general anesthesia and open heart operation.
The current TandemHeart PTVA system is a percutaneous left ventricular assist system comprised of a centrifugal pump, a 21 Fr, .about.65 cm long uptake cannula designed to be placed across the interatrial septum using standard transseptal puncture technique, and a 15 or 17 Fr return cannula; with the cannulae connected to the pump using standard ⅜ inch surgical tubing. Systemic flow rates of 3.5-4.0 Liters/Min. can be achieved. This device has been studied on acute cardiogenic shock patients and was found to confer a significant hemodynamic benefit compared to the intraaortic balloon pump (IABP). It is currently approved by the FDA for temporary (<6 hr) left ventricular mechanical circulatory support, and based on the results of the cardiogenic shock trial, will likely receive an FDA approved indication in the setting of acute cardiogenic shock due to left heart failure.
There are three previous publications on the topic of percutaneous right ventricular assistance. Two are by Yano (Trans Am Soc Artif Organs 1993; 39:120-25, Ann Thorac Surg 1996; 61:1231-35). These report on the same work, one preliminary and the other with more data. The third is from Matsuo with Yano as the second author (Artif Organs 2000; 24:148-55). This is from the same group and is very similar to the other two reports.
These papers report the results of right ventricular assistance in experimental animals, using custom designed cannulae and off the shelf centrifugal pumps. The cannulae are prototypes and not available on the commercial market. The pumps are commercially available devices, typically used for cardiopulmonary bypass. These pumps are for short-term use during surgery and should not be considered as ventricular assist devices. In all of the experiments, the right-side assistance was used in conjunction with left side support. The original paper was in 1993 and it has not been applied in a patient by this group.